TWICE-daily cephalexin has been found as effective as a regimen of four daily doses, when treating females with uncomplicated urinary tract infection (uUTI). This research is compelling when one considers that a large percentage of uUTIs do not respond to first-line treatments, as a result of high rates of antimicrobial resistance.
Aidan Yetsko, Trinity Health Grand Rapids, Michigan, USA, described: “Conflicting data exist regarding optimal dosing, with most reference material historically listing four-times-daily regimens while pharmacokinetic data support twice-daily dosing.”
Researchers conducted a retrospective, multicentre cohort study, during which they assessed adult females receiving 5–7 days of cephalexin for symptomatic uUTI with a cefazolin susceptible urine culture. The primary objective in this work was to compare uUTI treatment failure between patients treated with the two treatment options, but secondary outcomes included time to treatment failure, reported adverse events within 7 days, and occurrence of Clostridioides difficile within 30 days. In the cohort, 261 patients were included: 173 in the 500mg twice-daily group (BID), and 88 in the four-times-a-day regimen (QID). Escherichia coli was the most commonly detected pathogen (85%).
According to results, the researchers found no difference in treatment failure between groups (BID group: 12.7% versus QID group: 17%; P=0.343), including failure while on therapy (BID group: 2.3% versus QID group: 5.7%; P=0.438), or recurrence within 30 days (BID group: 10.4% versus QID group: 11.3%; P=0.438). Plus, there was no significant difference in reported adverse events (BID group: 4.6% versus QID group: 5.6%; P=0.103).
Yetsko concluded that cephalexin dosed 500 mg twice-daily is as safe and effective as the four-times branch, based on these results and applicable to treating females with uUTI. Yetsko added: “The twice-daily dosing strategy may also help prompt prescribers to select cephalexin over more broad-spectrum oral cephalosporins, which may have historically been selected due to less frequency dosing recommendations.” This study is promising, and should improve patient adherence and satisfaction with treatment as clinicians work this into practice in the near future.